Brian Kelly (Twitter: @brpkelly)

FERGUSON, MO (KMOX)  With the chants of angry protestors audible in the background, St. Louis County police chief Jon Belmar told reporters that the 18-year-old shot by a Ferguson police officer Saturday, had struggled with the officer over his sidearm.

Belmar says that the officer had ‘an encounter’ with two individuals on the street. Belmar says as the officer tried to get out of his car, one of the subjects pushed him back in and began assaulting him, “It is our understanding, at this point in the investigation, that there was a struggle over the officer’s weapon. There was at least one shot fired within the car.”

Belmar says after the officer got out of the car, he shot Michael Brown about 35 feet from the vehicle.

“More than a few” shell casings were recovered from the scene, according to Belmar, all were from the officer’s gun. He says it’s not clear how many times Brown was shot, “It was more than just a couple, but I don’t think it was many more than that.”

He did not say what led to the initial encounter.

The medical examiner is conducting an investigation to determine how many times Brown was shot. It could take up to six weeks for toxicology tests to be completed.

Belmar pointed out that Ferguson police chief Tom Jackson called him personally as he was arriving at the scene on Canfield Drive, and personally asked the county to investigate the shooting, “I would not imagine that anybody would do that if they felt like they had anything to hide or in fact did not want the investigation to be looked at independently and then the facts and circumstances of that investigation be looked at by a neutral party.”

Belmar says when the investigation is complete, the results will be turned over to St. Louis County prosecutor Bob McCulloch.   He says there’s a chance the FBI could be involved in the investigation, saying that’s not unusual.

Belmar says the officer involved in the shooting has been on the force about six years and had no history of similar incidents. He is on paid leave pending the investigation.

Belmar’s comments did not please demonstrations who began protesting outside Ferguson police headquarters an hour before the press conference.

Organizers are calling for 10,000 people to show up Sunday to carry on the protest.

At one point a rumor spread that the witness to the shooting had been found dead behind a nearby pizza restaurant. It was later confirmed that was not the case.

KMOX’s Michael Calhoun (Twitter: @MichaelCalhoun) reports one man called for violence against the police, but someone in the crowd shouted, “Young man, listen to the older man.”

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